Printing the future

Ask most people what they think of when they hear the term “additive manufacturing” and, if they think of anything at all, it will probably be a 3D-printed plastic curio from a digital design, says David Wimpenny, chief technologist at the Manufacturing Technology Centre


The ability to grow a three-dimensional object by printing hundreds of microscopically thin layers of material is already revolutionising some industrial processes and could well become one of the most dramatic shifts in manufacturing since the advent of mass production. Little wonder the government is investing so much in supporting the development of additive manufacturing methods.

The technology is already in use in manufacturing, producing low-cost pre-production prototypes or making the tools and fixtures to support conventional manufacturing methods, dramatically reducing product-development cost and lead times.

But that is just the tip of the iceberg. The real impact of this technology is felt when it is used to make end-use products. At the moment there are only a few examples of real additive part production. These include high-performance medical devices and aerospace parts. However, the possibilities are endless. We are already starting to see examples of additive manufacture of customised dolls, footwear, clothes, food and even full-sized buildings.

It’s no exaggeration to say that almost every field of human endeavour, from how we travel, to what we make and use in everyday life, to what we eat, to how we treat injury or illness is likely to be touched by this revolutionary technology.

The strength and integrity of components and products made by additive manufacturing often exceeds that of conventionally produced parts. Complex shapes and structures can be made with no joints or weaknesses. Imagine a bicycle made as a single structure with no welds or brazed joints, just a seamless tubular structure.

NEW ENTREPRENEURS

Additive manufacturing enables parts which are too complex to be produced using existing manufacturing techniques to be made at the touch of a button. This is giving designers unrivalled freedom, unlocking their creativity and fostering a new generation of entrepreneurs able to explore new market opportunities without the high barriers to entry associated with conventional manufacturing.

Moreover, it is possible to make a single part which is composed of several materials, each printed precisely where required to give the desired properties. This ability to design the material at the same time as designing the shape is a unique characteristic of additive manufacturing which will keep the best material scientists in the UK busy for decades to come.

But these concepts are for the future and there’s still work to be done in terms of quality assurance, materials development and product testing, as well as increasing the speed of the additive manufacturing process to support higher-volume production.

It could be years or even decades before the full capabilities of additive manufacturing are properly understood. But in the here and now it is having an impact on some of the more mundane aspects of production, and it is here where early wins can be achieved in cost of production, time saved and materials not wasted. It is vital that industry exploits the technology currently available, as well as planning for the future.

It’s no exaggeration to say that almost every field of human endeavour is likely to be touched by this revolutionary technology

Additive manufacture was first identified as a viable process back in the mid-1980s, but it is only recently that its enormous potential has begun to be understood. It started out as a tool for rapidly producing models and prototypes of new products, but it has evolved into a method of producing end-use parts.

There can be no doubt that, even at its most basic, it has significant advantages over conventional manufacturing methods. Unlike formative processes, such as casting, pressing or moulding, it does not require expensive tooling and unlike subtractive methods, such as milling, turning or grinding, it produces very little material waste, and there is virtually no penalty for complexity.

The driver for continued development of this exciting technology is coming largely from the aerospace sector. The industry is under enormous pressure to comply with stricter environmental regulation, as well as the obvious requirement to stay competitive in a rapidly expanding market. This is driving the need for a step-change in materials and component design as producers strive for higher-performance materials at extreme temperature, reduced weight and improved fuel efficiency.

A solution is the use of additive manufacture for complex metal parts and, more recently, ceramic parts which can withstand higher temperatures.

GROUNDBREAKING TECHNIQUES

At the Manufacturing Technology Centre, near Coventry – an acknowledged world leader in additive technology and now the home of the National Additive and Net Shape Manufacturing Centre – we are doing groundbreaking work in this field with our partners from industry and academia. As part of the High Value Manufacturing Catapult – a network of technology centres established by the government in 2011 – our role is to ensure that new manufacturing techniques are commercialised and exploited in the UK.

The technology has the capability to save millions of pounds in product-development and manufacturing costs, as well as providing an efficient route to remanufacture of damaged or worn parts which would previously have been scrapped.

Developing any product is an expensive business, but additive technology can take a huge bite out of the most expensive parts of the process – prototyping and tooling. Low-volume tooling production by traditional methods is a major part of the product-development cost, so the advantages of being able to print tools which perform more efficiently using additive manufacturing are clear. And the benefits of printing parts on demand can be reaped if you’re working in a metal-bashing factory in the Midlands or on a space station orbiting the Earth.

The imagination doesn’t have to go far to see wider benefits in other applications. The possibilities of the technology in our hospitals are already being studied. 3D anatomical models are helping surgeons plan complex operations, saving the NHS millions of pounds each year and improving patient treatment. The potential to print replacement organs may seem far-fetched, but additive manufacture is key to some major breakthroughs in tissue engineering.

Although these concepts may seem like science fiction now, it is important for industry not to lose sight of the current applications of a technology which is undoubtedly here to stay. The tipping point will be when additive manufacture moves into mainstream manufacturing, with machines capable of volume production. It will come and it represents a significant challenge to the manufacturing sector – but it also brings limitless opportunities.